Hoist



r 1,632,571 June 14, 1927. A. s WATSON HOIST Filed Jan. 19, 1925 2 Sheets-Sheet 1 E174 ARCHIE/4L0 & WATJU/Y P/SM Gm);

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June 14, 1927.

A. S. WATSON HOIST Filed Jan. 19, 1925 MiIZi/Jy/JJIYMIAWMiZ/lil/ l l l l l llll l l l Patented June 14, 1927.

UNITED sTA r E s PATENT OFFICE.

ABCHIBALD S. WATSON, OI DETROIT, MICHIGAN, ASSIGNOR TO DETROIT .HOIST AND MAOHDIE COMPANY, OF DETROIT, MICHIGAN, A. CORPORATION OF MICHIGAN,

noIs'r.

Application filed January The invention relates to hoists and refers particularly to a novel arrangement of gears therefor. A further feature of my invention resides in the provision of gearing inherent- 6 ly self locking whereby the load is held in hoisted position.

It is customary in hoists of this character to provide a unit called a load brake for holding the load in any hoisted position without the aid of any external power. A feature of my invention includes a spur gear hoist which will hold the load without requiring the heretofore necessary load brake.

A further object of my invention is to Q5 provide an efiicient hoist which has com paratively few parts and which can be cheaply manufactured and assembled.

With these and other objects in view, the invention resides in the'novel features of construction and combination and arrangements of parts as more fully hereinafter described claimed.

Referring to the drawings Figure 1 is/b. plan view of the hoist;

Figure 2 "represents a sectional view through the hoist showing the arrangement of gears, and

Figure 3 indicates a perspective view showing the locking gears.

In the drawings reference character 10 designates the frame of the hoist rotatably supporting the hoisting drum 11 which is fixed to the rotatable drum shaft 12. '13

indicates a drive shaft receiving power preferably through reduction gears 14, 15 from any suitable source such as an electric motor 16. Freely mounted on the drum shaft 12 is a gear 17 driven from a pinion 18 fixed to the drive shaft 13. 19 is a stud carried by the gear 17, the stud carrying a driving pinion 20. Meshing with the pinion 20 are the two gears 21 and 22, the'former being keyed to drum shaft 12 and the latter being rotatably mounted on the drum shaft but held fixed by a pin 23 carried by the drum frame.

The gears 21 and 22 are of equal pitch and outside diameters, but unequal in number of teeth. For example, the driven gear 21 may have twenty-four teeth and the gear 22 may have twenty-two teeth although it should be understood that the number of teeth of these gears may vary. The tooth difi'erence between gears 21 and 22 may be 19', 1925. Serial n. 3,444.

o1 1e or more depending upon the number of PlIllOIlS '20 employed.

The arrangement of gears as described provides a self locking mechanism. By applying power in either direction from the motor 16 to the drive shaft 13 and pinion 18, the gear 17 will be correspondingly driven carrying with it the pinion 20. The latter P1111011 rolling around the fixed gear 22 will rotate the gear 21 and therefore the drum 11 in a direction corresponding to that of the drive. However, by applying power or load to the drum 11, the gear train will become locked preventing movement of the drum exxcept by reason'of power applied to the drive shaft 13 from the motor end.

In driving the gears from the motor end, as in hoisting or lowering a load, the teeth of the pinion 20 act as wedges tending to bring the faces of the teeth of gears 21 and 22 into alignment. Since gear 22 is held fixed movement is thus imparted to the gear 21 whichin turn moves the drum 11. By stopping the application of power applied to drive shaft 13 from the motor, the teeth of pinion 20 act as keys preventing rotation of gear 21, thus holding the load in any osition.

. ile it is believed that from the foregoing description, the nature and advantage of my invention will be readily understood, I desire to have it understood that I do not limit myself to what is herein shown and described and that such changes may be resorted to when desired as fall within the scope of the claims What I elaimas my invention is 1. In a hoist, a frame, a drive shaft, a

drum shaft, a drive pinion on the drive shaft, a drum on the drum shaft, a driven gear fixed to the drum shaft and a second gear loosely mountetd on said drum shaft, the latter gear meshing with the said drive pinion, a pinion carried by said second gear and meshing with the said driven gear fixed to the drum shaft, and a stationary gear fixed to said frame and meshing with said last named pinion, the latter gear and the said driven gear fixed to the drum shaft having a different number of teeth.

2. In a hoist, a frame, a main shaft journalled in opposite sides of said frame, a drum fixed to said shaft, an external gear concentrically journalled on said main shaft and fixed to said frame so as to remain staa stud mounted adjacent the peripher of tionary, an external gear concentrically said driving gear, a pinion journalle on keyed to said main shaft adjacent the first said stud adapted to mesh with said two ex- 10 said external gear, said two external gears ternal gears.

5 having the same outside diameter and pitch In testimony whereof I afiix my signature.

of teeth but unequal numbers of vteeth, a driving gear journalled on said main shaft, ARCHIBALD S. WATSON. 

